VTEncoderXPCService hogging CPU via Vivaldi

The Mac services VTEncoderXPCService and com.apple.photos.VideoConversionService are hogging my CPU. At times both using over 100% of a core each. Any thoughts on why this is happening? 2010 Macbook Pro with El Capitan and latest Vivaldi. I closed all tab except for this one and they still run. If I quit Vivaldi the processes quit too. If this is how it's going to be I can't use Vivaldi. UPDATE: So today no problems, those processes are nowhere to be found. I'm perplexed, but happy that Vivaldi is not causing the CPU issues.